Old Hats should go some way toward checking the bad rap that clowns and mimes have gotten in recent years. Its astonishing stars, Bill Irwin and David Shiner, are physical comedians of the highest order, with roughly 75 years of mirth-making between them—including their collaboration Fool Moon, a beloved vaudeville that returned to Broadway twice after its 1993 debut. Their reunion at the Signature, directed by Tina Landau (and tricked out with G.W. Mercier’s costumes and set), finds them older but splendidly limber. As always, Irwin’s air of affability is offset by Shiner’s spikier mien. When the two perform in sketches together—as codgers trading pills on a train platform, say, or as a sleazy magician and his jealous wife—their polymorphous complementarity leaves the audience buzzing with joy.

Old Hats is a variety show not just as a whole but in each of its constituent parts. Clowning at this level is already an amalgam of comedy, theater and dance; here it is also boosted by a constant flow of music from a terrific band of five, led by the subversively chipper singer-songwriter Nellie McKay. Between bits and bouts of clowning, McKay performs many of her own songs, spiking Old Hats’ punch with her unique brand of retromodern wit. A few of the routines are recyled from Fool Moon or drawn from the performers’ deep trunks of material—Irwin has been playing his spaghetti-wrestling waiter since the 1970s—but most of the show was new to me. (One highlight among many: Shiner’s touching “Hobo” sequence, in which a lonely vagrant fashions a companion from detritus on a park bench.) If you let yourself miss this marvelous diversion, the more fool you.—Adam Feldman